Setup for a wine bottle with multiple labels
Create an object that surrounds the bottle, but it's but that is just a bit bigger than the bottle (to avoid Z fighting errors). Unwrap it to get something like this:



Assign a texture using the alpha channel of the texture to control a transparent shader. A mapping node will also help you with the positioning of the label.



Now by changing the image on the Image texture node (and sometimes the scale and placement) you can preview your different labels.



A blend file to play: